Electric switch



Aug. 7, 1928.

A. H. NERO smacrmc swmcn Filed Jan. 1923 INVENTOR HRH/1U h. NEEO BY m ATTW Patented Aug. 7, 1928.

UNITED STATES 1,679,442 PATENT OFFICE.

ARVID H. NERO, 0! NEW -IBRITAIN, CONNECTICUT, ASSIGNOR TO THE ARROW ELEC- .TRIC COMPANY 01 HARTFORD, CONNECTICUT, A. CORPORATION OF CONNECTICUT.

nrno'rmc swrrcn.

Application filed January 10, 1923. Serial No. 611,765.

My invention relates to electric switches, and particularly to rotary snap switches. The object of my invention is to provide improved dial means for indicating various positions of the switch mechanism.

In the accompanying drawings-- Fig. 1 is a broken side elevation of a rotary snap switch to which my invention is applie in one form;

Fig. 2 is a horizontal section throu h the switch spindle above the indicating ial;

Fig. 3 is a similar view taken below the rotary dial; and

Fig. 4 is a broken side elevation of-a modified form of cov r.

The invention is illustrated in a rotary snap switch of theheater type adapted to control the various circuits of a resistance unit for electric ranges or the like, and is of the type shown in the copending applications of Carlson, Serial Nos. 599,506 and 600,137, although the switch mechanism as a whole may be of any suitable character. The switch comprises an insulating base 5 on which is supported the switch spindle 6 operated by means of the thumb piece 7. The switch mechanism is actuated by the rotation of the spindle, and is housed within the cover 8 and its insulating lining 9. The operative engagement between the thumb piece 7 and the switch spindle 6 is obtained through a laterally projecting fin 10 on the spindle 6, which engages a washer 11 held by a spring 12 in the hub 13 of the thumb piece and rotating with the latter by reason of the engagement of the lug on the washer in' the lateral channel 14 formed in the hub. The fin 10 on the spindle is preferably of considerable longitudinal extent, and the hole 15 in the cover 8 through which the spindle passes is of sufiicien't diameter to accommodate the fin and permit its free I rotation therein.

In the construction illustrated in Figs. 1, 2 and 3, there is interposed between the bearing washer 16 of the thumb piece and the upper surface of the cover 8, a rotary indicating dial 17 apertured at 18 to accom-' modate the switch spindle and slotted at 19 to afford an operative engagement with the fin 10 on the latter so that the dial is rotated with the spindle. In its preferred form the dial is struck from sheet metal and shaped as shown to afford a marginal incline 20, in which the legends 21 are formed at appropriately spaced points, which come successively into register with a cooperating pointer 22 formed on the exposed margin of the cover. 8; For a heater switch, the legends SOIlStltlltG the usual indications for the off low medium and high positions of the switch mechanism. If the invention is applied to a switch having only make and break positions, the legends would the central portion of the dial is oifset to afford a central depresm'on23 which accommodates the hub 13 of the thumb piece 7 The mid-area 24 of the dial is preferably flat to afford an appropriate bearing for the handle, and in turn to afford an appropriate bearing surface resting upon the shallow central boss 25 of the cover 8. The construction has the advantage of presenting the legends 21 in a position in which they may be readily viewed when the switch is installed on the front of a range, while at the same t1me maintaining the over-all axial dimenslons of the switch as low as possiblea feature of great practical importance in a range swltch, which must be large enough to handle. heavy current safely, and at the same time should be as compact as possible, not only for the neat appearance of the installation, but also to prevent injuryto the switch in its exposed position.

When a rotary dial of the type described is employed, the thumb piece may be of nonswitch cover. may be shaped as shown in Fig. 1

4 to follow the same general cross sectional form indicated for the rotary dial, in which case a thumb piece 26 of the pointed type indicated in Fig. 3 will be substituted for that shown in Figs. 1 and 2, and by the registry of its indicating ointer with one or the other of the legen s formed on the stationary cover, indicate the position of the switch mechanism.

The present invention also comprises a novel legend formation. To this end the metal-of the dial (whether in the cover or a separate disc) is deformed in a press to raise legend characters 27 above the level of the adjacent surface of the dial. Preferably the surface of the dial in the legend zone is depressed to form an annular channel concentric with the spindle hole 15, from the bottom of which channel the legend characters rise to the level of the margins of the channel. The channel is then coated and in fact substantially filled (see Fig. 4) with a suitable finishing composition which may, for instance, be a black enamel or paint, or other material. This may be accomplished by dipping, or by brushing the finish over the surface of the dial. After the finish has been thus applied to the dial surface, it is removed from the raised surface of the legends and from the margins of the dial by any suitable means, as, for example, a burnishing wheel or the like, with the result that the raised metal characters stand out with great clarity from the back-ground afforded by the finish. If the dial be made of aluminum, or other non-oxidizing material, and the finish coating of some composition of contrasting color, the permanent brilliancy of the legends is quite remarkable while the burnished outline of the legend channel or depression adds greatly to the attractiveness of the cover appearance.

This method of forming the legends may of course be applied to any dial, for example to the upper surface of the cover, as indicated at 28 in Figs. 1 and 3, and in the sub-joined claim I use the word dial to indicate, where appropriate, the dial surface of the switch cover itself.

It will be observed that in the construction illustrated in Figs. 1, 2 and 3, there are in fact two dials, one, the upper face of the stationary switch cover, and the other, the rotary disc dial which overlies the cover.

This construction makes it ossible to use the switch either with or wit mat the rotary dial 20 to meet the wishes of the customer, and without disturbing the installation further than the unscrewin of the switch handle, inasmuch as the dial is held in position by the handle and is readily slipped on or off the spindle, with which it is engaged only through the fin 10.

In the following claim, the term cover element is employed where appropriate, in a sense broad enough to include either the upper surface of the cover or the rotary disc dial. The invention is not limited to the precise forms illustrated, which may be modified without departing from what I claim as my invention.

I claim A rotary snap switch comprising an insulating base, a rotary switch s indie rising therefrom and having a laterally projecting actuating member, 'a switch cover element having a legend-carrying marginal area inclined to the axis of the spindle, and a depressed central area substantially normal to the spindle and apertured to permit the spindle and laterally projecting member to pass therethrough and rotate, together with a handle mounted on the spindle and having an operative engagement with said laterally projecting member, said handle having a hub portion bearing on the central depressed area of the cover element, and a finger grip portion overhanging the legend-carrying marginal area of the cover element.

In testimony whereof I have signed my name to this specification.

ARVID H. NERO. 

